One of the most common types of physical rehabilitation equipment is the isokinetic machine, a type of dynamometer used for measuring and stressing muscles in the arms, legs, and trunk. This proposal is for a new class of isokinetic machine offering 1) quantitative assessment of patients condition and impairment and 2) passive range of motion therapy for paraplegic and quadriplegic patients 3) improved rehabilitation therapy. The proposed machine will benefit not only patients and the physical therapists who treat them, but also employers, insurers, and HMOs concerned about cost- effective rehabilitation programs. The proposed device is an isokinetic machine that can generate and measure both position and force in six degrees of freedom simultaneously along any path. Such a device would have significant advantages for both evaluation and treatment. We call our device the Multipurpose, Multiaxial Isokinetic Dynamometer (MMID). A machine like the MMID would be particularly advantageous because of its modular nature, potential ease of set-up and attachment, and the ability to passively range many joints simultaneously and repetitively. For example, modules could be attached to the foot to move the entire leg into alternating flexion and extension with components of hip abduction-adduction and internal-external rotation controllable with units attached by cable above the knee. PROPOSED COMMERCIAL APPLICATIONS: The potential market for an improved isokinetic device is large. The patient base is enormous. Millions of injured, aging, or athletic people visit clinics and private practitioners for treatment of musculoskeletal problems. Millions of others who need therapy are suffering from neurological impairments such as stroke or spinal injury. The potential buyers of the machines may number in the tens of thousands: clinics (free-standing and within hospitals), health clubs and college athletic departments- researchers in universities and government agencies.